#ratelaw

Rate law describes how fast a reaction will take place.  You can distinguish rate law from equilibrium because it only takes into account the reactants in the equation.  You must also note that the superscript x and y in rate law are not synonymous with the stoichiometric coefficients in the written reaction unless it meets a few conditions.  These conditions are: that reaction is perfectly balanced, is only one step, or includes all of the information such as the rate limiting step.   The MCAT typically only focuses on zero, first, second and third order reactions.  The order of the reaction is determined by the sum of the x and y superscript values. 

Remember that the values k, x and y in the equation are only determined experimentally.